From what I hear, the location will reopen as a Daylesford shop i.e. pricey dairy, grocery and lifestyle goods probably. With the loss of Starbucks from the high street as well, Marylebone is gradually becoming less and less family friendly. Pizza Express and Carluccios are still reliable family favourites so fingers crossed they also don't get priced out of the market too! (Btw, did you know Giraffe is owned by Tescos? I didn't)
There are other cafes and restaurants locally that are happy to host families e.g. Natural Kitchen and others, though not all have baby changing etc so do ask when you are there. Others don't always have space for prams, or only have 1-2 high chairs available. Chiltern Firehouse has a great courtyard and high chairs, but weekends they only serve food from 11am - they are ignoring a great opportunity there!
Marylebone is a hot spot right now, but we must make sure that there are still family friendly businesses here too.